Method and apparatus for drafting and coiling sliver



p 1968 c. w. SCHWALM METHOD AND APPARATUS FOR DRAF'TING AND COILING SLIVER 3 Sheets-Sheet 1 Filed Sept. 22, 1965 INVENTOR CLAIR W. SCHWALM ATTORNEY p 4, 1968 c. w. SCHWALM 3,402,433

METHOD AND APPARATUS FOR DRAFTING AND COILING SLIVER Filed Sept. 22, 1965 5 Sheets-Sheet 2 44 III .-a2 28 O 67 66 a 1// \I 39 C 20 \\\\\\Y\\ \WI /9 K I x 70 39 6 6 73 72 3" INVENTOP CLAIR W. SCHWALM ATTORNEY Sept. 24, 1968 c. w. SCHWALM 3,402,433 METHOD AND APPARATUS FOR DRAFTING AND COILING SLI VER Filed Sept. 22, 1965 3 Sheets-Sheet 5 INVENTOR" CLAIR W. SCHWALM ATTORNEY United States Patent 3,402,433 METHOD AND APPARATUS FUR DRAFTING AND COILING SLIVER Clair W. Schwalm, Greenvilie, S.., assignor to Benjamin Booth Company, Greenville, S.C. Filed Sept. 22, 1965, $82. N0. 489,309 7 Ciailns. (Cl. 19-159) ABSTRAQT OF THE DESQLUSURE The invention relates to sliver drafting and ceiling wherein the former occurs between sensing means driven at constant speed for detecting variations in sliver thickness and drafting means driven at variable speeds in accordance therewith, such means located above a coiler or tube gear and a sliver can which are driven at con stant speed. The coiler or tube gear is provided with a tube having a progresssively larger diameter towards the can thereby permitting the deposition of sliver within the can in a plurality of multiradius configurations.

This invention relates to a coiler and the like for producing slivers of more nearly uniform weight or thickness.

Usually no attempt is made to reduce irregularities in sliver coming from a card, such sliver being deposited in a can driven at a continuous and uniform speed through a tube of uniform cross-section also driven at a continuous and uniform speed. However, in order to produce high quality thread or yarn it is desirable that the sliver have a minimum of irregularities in cross-section. In many cases sliver coming from a card will vary considerably in weight or thickness from point to point along its length, and therefore, high quality yarn or thread cannot be produced therefrom.

One attempt to produce an even sliver contemplates drawing six slivers at the same time and then uniting them into a single sliver of approximately the same weight as one of the previous six slivers. The inequalities in the single slivers are, therefore, averaged to produce a reasonably even silver for spinning. In such a process it Will be apparent that the drafting of each of the slivers to reduce them to one-sixth of their original weight, sometimes, rather than producing an even final sliver, increases the unevenness. Sue-h result is obtained due to a thin section tending to become more thin and the thick sections tending to retain their knotty condition and, therefore, to remain thick. Moreover, if at one particular point several thin sections or several thick sections are united, then the unevenness of the final sliver is amplified rather than minimized.

Other attempts to produce an even sliver contemplates using a drafting device which incorporates a sensing means in conjunction with a pair of drafting rolls. The sliver coming from the card is fed through the sensing means which produces a signal responsive to irregularities in the incoming sliver. The sliver then passes from the sensing means to the drafting evener rolls, and these rolls are either speeded or slowed from their previously adjusted drafting speed, according to the requirements of the sliver. The sliver is then delivered at an uneven rate to the coiling mechanism and usual can in which it is coiled and stored for further operation. In such systems it is imperative that the control of the speed of rotation of feed rolls, the coiler can and the tube gear be dependent on the speed of the sliver delivery to insure even take-up of the sliver in the can without stretching or further drafting of the sliver.

If a constant diameter coiler tube were used and the can and tube gear were rotated at a constant speed while 3,402,433 Patented Sept. 24, 1968 the drafting operation were carried out, then when the drafting rolls slow below their normal speed, drafting would take place between the coiler tube and the can producing irregularities. If the speed of the drafting rolls were increased, then the sliver would tend to gather in the coiler tube. Thus, it can be seen that the speed of rotation of the can and the tube gear must be varied with the drafting rolls. The great majority of the load when uniformly varying the speed of the can, the tube gear, and the drafting rolls is due to the can and tube gear. Such a large load often causes a breakdown in the variable speed transmission device. In attempting to reduce the load and avoid undesired drafting between the tube gear and the can, one device eliminated the tube gear. In such a device the sliver is merely fed into a rotating can and deposited about the center axis of the can. The amount of sliver that can be deposited in the can without tangling is less than when the sliver is deposited in a multiradius configuration about the center axis of the can.

Accordingly, a principal object of the present invention is to provide a novel and improved sliver control mechanism in which a uniform size sliver is deposited in a can.

Another object of this invention is to provide a sliver handling device which automatically and continuously compensates for the unevenness of a sliver resulting in a sliver of more nearly uniform cross-section.

A further important object of this invention is to provide a device for depositing sliver into a sliver can without undesired drafting taking place between the delivery tube and the can.

Still another important object of the present invention is to provide an automatic leveling device which reacts to maintained fluctuations in the weight of the sliver passing therethrough.

A further object of the present invention is to provide a coiler tube having a tapering progressively larger crosssection toward a uniformly driven sliver can to permit sliver to be fed therein without obstruction while the flow of sliver varies responsive to variations in sliver thickness.

Another object of the present invention is to provide a coiler tube in which sliver can be fed therethrough at varying speeds while the speed of the tube gear relative to the sliver can remains constant.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown and wherein:

FIGURE 1 is a schematic elevational view of a sliver handling device constructed in accordance with the present invention,

FIGURE 2 is an enlarged perspective view of the upper portion of the device illustrated in FIGURE 1,

FIGURE 3 is a transverse sectional elevation taken on line 3-3 in FIGURE 2,

FIGURE 4 is a longitudinal sectional elevation taken on line 4-4 in FIGURE 2,

FIGURE 5 is an enlarged fragmentary perspective view of the damping mechanism illustrated in the upper lefthand portion of FIGURE 2, and

FIGURE 6 is a top plan view on an enlarged scale of the sliver handling device.

The drawings illustrate a sliver coiler and the like having a sliver can A, driving means which rotates the sliver can at uniform speed, and a tube gear B which is driven by the driving means at uniform speed. A first pair of drafting rolls C are positioned above the sliver can for feeding sliver for reception by the sliver can. A second pair of sensing rolls D are driven at a uniform speed and are positioned above and in alignment with the drafting Q a) rolls. One roll of the second pair of sensing rolls D is responsive by lateral displacement to variations in sliver thickness. A damping and time-delay means E is responsive to the lateral displacement of the one roll and provides a damped and time-delayed signal indicative of maintained variations in the thickness of the sliver. A variable speed transmission F through which the drafting rolls are driven is controlled by the damped and timedelayed signal for varying the speed of the drafting rolts C. A coiler tube G is carried by the tube gear B and has an intake orifice which receives the sliver from the drafting rolls. An outlet orifice of the coiler tube G is substantially larger than the intake orifice and is located opposite the intake orifice within the tube gear B. The coiler tube presents a progressively larger path for the sliver as the sliver progresses from the drafting rolls into the sliver can. Thus, variations in sliver speed may be accommodated by the coiler tube without excessive distortion of the sliver thereby, and variations in sliver thickness are reduced by the drafting which occurs between the second pair of rolls and the drafting rolls.

Referring more particularly to FIGURE 1 of the drawings a web 6, which is delivered from a carding machine by the usual doffer roll (not shown), is fed into calender rolls 7 to form a sliver 8. The sliver in turn is delivered to the sliver handling device by means of a trumpet 9 mounted thereon. The sliver is then leveled by the sliver handling device and deposited into a can A. The sliver can A is mounted for rotation on a base plate 10. The driving means for rotating the base plate 10 includes a horizontal shaft 11 which drives vertical shaft 12 through bevel gears 13. The horizontal shaft 11, in the preferred embodiment illustrated, is driven by the output mechanism of the carding machine, shown schematically in FIG- URE 1. Thus, there is direct relation between the rotation of the can, the drafting mechanism and the flow of sliver from the carding machine. The horizontal shaft 11 is coupled by a pair of spur gears 11a to a shaft 11b from which the calender rolls are driven. The shaft 1111 upon which the calender rolls 7 are driven may be driven in any suitable manner by the carding machine. The drive means for shaft 11b is carried in the vertical housing 11c which supports the shaft. The vertical shaft 12 is provided at one end with a gear wheel 14- which engages a gear wheel 15 connected to the base plate 10 upon which the can is carried. The vertical shaft 12 also carries a gear wheel 16 meshing with the tube gear B. The other end of vertical shaft 12 is in driving engagement with one of the measuring rolls D by means of bevel gears 17 and a horizontal shaft 17a. The details of such connection are discussed below. Thus, it can be seen that the entire coiler and sliver handling device is powered by the vertical shaft 12.

The tube gear B and the gear wheel 15, connected to the bottom plate 10, are both rotated at a constant rate of speed. However, the tube gear rotates at a considerably higher rate of speed than the can A causing the sliver to be distributed in circular configurations about the entire area of the sliver can A. While the can in the preferred embodiment is rotated at a constant speed relative to the tube gear, it may be desired to keep the can stationary and provide other suitable means for distributing the sliver in a plurality of multiradius configurations about the entire area of the can.

A first pair of drafting rolls C are positioned above the sliver can for feeding the sliver 8, shown in broken lines in FIGURES 1 and 2, for reception by the sliver can A. The two drafting rolls 19 and 20 which constitute the pair generally designated at C are rotated at the same speed but in opposite directions. Drafting roll 19 is rotated in a counter-clockwise direction while drafting roll 20 is rotated in a clockwise direction. The speed of rotation of the pair of rolls 1-9 and 20 varies according to the size sliver coming from the card. In the preferred embodiment oversized sliver, in the vicinity of twenty-five percent Cir oversize, is supplied by the carding machine so that the drafting rolls are always drafting thereby reducing the size of the sliver to the desired uniform thickness. The variable drive mechanism for the drafting rolls C is discussed below.

A second pair of measuring or sensing rolls D are driven at a uniform speed and are positioned above and in alignment with the drafting rolls. Roll 21 of the measuring rolls is responsive by displacement to variations in the slivers thickness. Roll 22 is not displaceable and is driven at a constant speed. The displaceable or sensing roll 21 is free running, and its rotation is caused by the frictional contact with roll 22 and the sliver passing therebetween.

The roll 21 is mounted on roller bearings 23 which are carried by a cam 24. The cam 24 is eccentrically supported by the scanning roll shaft 25 and is fixed thereto by a key, not shown, or by any other suitable means. The scanning roll shaft 25 extends through housing 26 and is supported therein by a pair of bearings which are not shown. One end of the scanning roll shaft 25 has a cap 28 attached thereto by a set-screw 29. The cap 28 has a cylindrical hole 3% therein, shown in broken lines, for receiving a laterally extending portion of the end of a spring 31. The other end of the spring 31 has a laterally extending portion which fits into a cylindrical hole 32 in the side of housing 26. The scanning roll shaft 25 is torsionally biased by spring 31 thereby tending to maintain displaceable roll 21 adjacent roll 22.

The roll 22 has a groove 33 in its outer surface through which the sliver passes. The roll 21 has a ridge 34 on its outer surface which fits into the groove 33 on roll 22 in a tongue and groove relationship. As sliver passes through the groove 33, the oversized portions tend to laterally displace the roll 21 from roll 22. Since roll 21 is eccentrically supported on bearings 23, a twisting motion is imparted to the scanning roll shaft 25. This twisting motion is transferred via a pulley 35 mounted on the end of the control shaft 25 through a metal band 36 carried thereon to the damping device E mounted on a control shaft 38 on the variable speed transmission F. In the embodiment illustrated, the variable speed transmission used is manufactured by Floyd Variable Drives, located in Denver, Colo., and is referred to as the A56 Drive. The speed of rotation of the drafting rolls C is cont-rolled by the variable speed transmission F, and any angular variation of the control shaft 38 causes the speed of the drafting rolls to be varied accordingly.

Power to drive the roll 22 and the pair of drafting rolls 19 and 20 is provided by the rotating horizontal shaft 17a. The shaft 17a is rotatably supported in the housing 26 on a pair of bearings 32. A pinion 40 is carried on shaft 17a in meshed relationship with gear 41 carried on shaft 42 to drive roll 22 at a constant speed. Shaft 42 is rotatably supported in housing 26 on a pair of bearings 43 and 44. One end of the shaft 42 terminates in bearing 4-3 while the other end has roll 22 mounted thereon by means of a key or any other suitable means.

The horizontal shaft 17a also drives the drafting rolls C through shaft 45, FIGURE 6, and the variable speed transmission F. The shaft 45 is rotated by shaft 17a through miter gears 46. The end of the shaft opposite the end on which the miter gear is carried terminates in an input gear box 47. The input gear box connects shaft 45 to an input shaft, not shown, of the variable speed transmission F through a plurality of gears which step-up the speed of rotation of the input shaft to the most desirable operating speed of the variable speed transmission.

As pointed out above, irregularities in the sliver passing between the measuring rolls D cause a twisting motion to be imparted to scanning roll shaft 25. The twisting motion is transferred by means of metal band 36 and the damping and time-delay device E to the control shaft 38 of the variable speed transmission, and causes the speed of rotation of an output shaft of the variable speed transmission F to vary. While variations in the rotation of the control shaft 38 are in degrees, the rotation of the output shaft of the variable speed transmission may be several hundred revolutions per minute.

Frequently occurring rapid changes in the sliver requires the variable transmission to react accordingly, and over -a period of time the variable speed transmission may be damaged by such rapid changes. In order to smooth out the rapid changes the damping device E is connected between the metal band 36 and the control shaft for the variable speed transmission. The damping device smooths out the changes as well as produces a short delay between the time when a signal is produced by the sliver passing between the sensing rolls D and the drafting change responsive thereto. It is desirable that the portion of the sliver that is to be evened by the drafting operation be between the sensing or measuring rolls D and the drafting rolls C.

The damping device B through which the control shaft 38 is rotated consists of a pulley 49 having a circumferential groove 56 therein for receiving the metal band 36. The pulley has a cylindrical hole in its center larger than the control shaft 38 permitting the pulley to ride freely on the control shaft. An arcuately shaped laterally ex tending semicircular member 51 is attached to the upper portion of the pulley and constitutes the outer face of the upper portion of the pulley 49. The arcuately shaped member 51 has a flat bottom surface. A rectangular shaped control arm 52 is carried on the control shaft 38 in spaced relationship with the flat bottom surface of the 'arcu-ately shaped member. The control arm 52 has a split 53 in one end permitting the control arm to be drawn tightly upon the control shaft 38 by means of a screw 54 carried between the split portions. A pair of springs 55 and 56 are carried in vertical cylindrical holes in the 'arcua-tely shaped member 51 each having one end extending out of the holes and in contact with the upper surface of the control arm 52. The pulley 49, with the arcuately shaped member 51, can be rotated on control shaft 38 Without turning the control shaft. When the pulley is rotated pressure is imparted through one of the springs to the control arm 52. The pressure on the control arm tends to rotate the control arm 52 which in turn rotates the control shaft 38. Quick rotation of the control arm is impeded by a double action dashpot 57 which is connected to the control arm. The dashpot 57 prevents any rapid rotation of the control arm. Thus, the variable transmission only receives signals indicative of maintained fluctuations in the thickness of the sliver. Therefore, relatively smooth signals are transferred to the control shaft 38. A suitable operating double action dashpot is manufactured by Electric Regulator Corporation, of Norwalk, Conn, and is referred to as Airpot.

Two laterally extending stops 58 and 59 project from the housing of the variable transmission restricting the movement of the control arm to a preselected number of degrees. The stop 58 prevents control shaft 38 from being rotated clockwise beyond a point where the variable transmission would not operate. The stop 59 prevents the control arm 52 from rotating in a counter-clockwise direction beyond a point where the variable speed transmission would reduce the speed of rotation of the drafting rolls C below the speed of the measuring or scanning rolls D. If the speed of rotation of the measuring D rolls were greater than that of the drafting rolls C, then the sliver would bunch or gather between the two sets of rolls obstructing the operation of the automatic leveling device.

The output shaft of the variable speed transmission F is coupled to an output gear box 59 which steps down the speed of rotation a proportional amount to that which the input gear box 47 stepped up the speed of rotation.

The drafting roll 19 is coupled by a shaft 60, shown in broken lines in FIGURE 6, directly to the output gear box 59. The other drafting roll 20' is coupled to the output gear box 59 through a pivotal gear box 61. The two drafting rolls 19 and 26 always rotate at the same speed relative to each other even though the drafting roll 20 is coupled to the output gear box via pivotal gear box 61. The pivotal gear box 6-1 permits drafting roll 20 to pivot relative to drafting roll 19 for cleaning and maintaining the desired pressure between the rolls. The pivotal gear box pivots about shaft 62 which extends from the output gear box 59 into the pivotal gear box 611. The shaft 62, which terminates in the pivotal gear box 61, has a gear 63 in meshed relationship with pinion gear 64. The pinion gear 64 is carried on one end of shaft 65 and drafting roll 20 is carried on the other end.

A spring biased plunger 66 is in contact. with the pivotal gear box 61 resiliently biasing drafting roll 26 against drafting roll 19. The plunger 66 is pivotable about shaft 67 permitting the pivotal gear box 61, with drafting roll 20, to be pivoted away from roll 19 for cleaning the rolls. The shaft 67 has a nut 68 threaded on one end for holding the plunger thereon. The other end of shaft 67 is attached to a laterally extending portion 69 on the output gear box 59.

A coiler tube G is carried by the tube gear 13 and has an intake orifice 70 which receives the sliver from the drafting rolls. The output orifice Ill for the coiler tube is substantially larger than the intake orifice and is located opposite the intake orifice within the tube gear B. The coiler tube G has a progressively larger diameter towards the can A permitting sliver to be fed thereby at varying speeds without obstruction that would be inherent in the standard uniform diameter coiler tube. The coiler tube G is supported by a guidance support '72 which is carried on the center of the tube gear. Since the flow of sliver to the can A varies while the speed of rotation of the tube gear B and the can A remain the same, it is desirable that a multiradius pattern be permitted to be deposited into the can Without drafting taking place. While: a coiler tube having a progressively larger diameter toward the can may be utilized, in the preferred embodiment it is thought that other guidance means, such as a flexible tube, can be utilized. Such a tube should be capable of depositing a multiradius pattern in the can without undesired drafting taking place.

The automatic leveling device is supported on a laterally extending member 73 which projects from a vertical standard 74. The vertical standard '74 also supports the coiler '75 in which the coiler gear B is rotatably carried.

In operation, the sliver 8 is fed from the card through trumpet between the sensing rolls 21 and 22. The eccentrically supported sensing roll 21 is displaced relative to stationary roll 22 responsive to irregularities in the sliver causing a twisting motion to be applied to the scanning roll shaft 25. The twisting motion of the scanning roll shaft 25 causes a twisting force to be applied to spring 31 which tends to maintain the scanning roll 21 adjacent roll 22.

The signal or twisting motion caused by the irregularities of the sliver 8 is transmitted to the variable speed transmission F. This twisting motion or signal is transferred via a pulley mounted on the end of the scanning roll shaft 25 through a metal band 36 carried thereon to a damping and time-delay device E mounted on the control shaft 38 of the variable speed transmission. The damping and time-delay device E smooths out rapid changing signals and supplies a smooth signal to the control shaft 38 of the variable speed transmission P, which is indicative of maintained fluctuations in the sliver thickness. The damping and time-delay device E incorporates a double action dashpot 57 which causes the signal being transmitted to the variable speed transmission to be timedelayed, as well as aiding springs and 56 in smoothing the signal.

When the control shaft 38 of the variable speed transmission F is rotated the speed of rotation of the output shaft is varied accordingly. The drafting rolls C are driven by the output shaft through the step-down gear box 59 and the pivotal gear box 61, thus variations in the control shaft 38 affects the drafting operation caused by the drafting rolls C. Since the signal received by the variable transmission F from the sensing rolls D is time delayed, the portion of the sliver that generated the signal is drafted while such is between the sensing rolls D and the drafting rolls C.

A coiler tub-e G is provided for receiving the sliver from the drafting rolls C and has a progressively larger diameter toward the can permitting the sliver to be fed thereby into the can A at varying speeds without obstruction that would be inherent in the standard uniform diameter coiler tube. The coiler tube G permits the path from the drafting rolls C to vary as the drafting operation changes, thus a plurality of multiradius configurations are deposited in the can A. Heretofore, the sliver has been deposited into the can in a constant radius configuration since the speed of rotation of the can and the tube gear are varied as the drafting operation varies. The subject invention permits a variable drafting operation to take place and the sliver to be deposited in a conventional can without the necessity of varying the speed of the coiler tube and the can. The sliver handling device has been described, as being driven by a carding machine; however, such may be utilized with any sliver producing machine and powered by any suitable drive mechanism.

While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.

I claim:

1. For use in a sliver handling device and the like having a sliver can, driving means rotating said sliver can, a tube gear driven by said driving means, the improvement including: a first pair of drafting rolls positioned above the sliver can for feeding sliver for reception by the sliver can, a second pair of rolls driven at uniform speed positioned above and in alignment with the drafting rolls, at least one roll of said second pair of rolls being laterally displaceable to variations in sliver thickness, a variable speed transmission for driving said drafting rolls, said variable speed transmission being controlled responsive to the lateral displacement of said one roll for varying the speed of said drafting rolls, and guiding means positioned between said drafting rolls and said can for permitting the deposition of said sliver into said can in a plurality of multiradius patterns, whereby variations in sliver thickness are reduced by the drafting which occurs between the rolls driven at uniform speed and said drafting rolls driven at a speed controlled esponsive to variations in sliver thickness.

2. In a sliver coiler and the like having a Sliver can in which sliver is deposited, driving means rotating said sliver can at constant speed, and a tube gear driven by said driving means at constant speed, the improvement including: a pair of driven drafting rolls feeding sliver for reception by the sliver can; means varying the speed of said drafting rolls responsive to variations in thickness of the sliver; a coiler tube carried by said tube gear having an intake orifice receiving the sliver from the drafting rolls, an outlet orifice substantially larger than said intake orifice opposite said intake orifice within the tube gear, and said coiler tube presenting a progressively larger path for the sliver as the sliver progresses from the drafting rolls into the sliver can, whereby variations in sliver speed may be accommodated by the coiler tube without excessive distortion of the sliver thereby.

3. The method of evening sliver and depositing the sliver in a sliver can, the steps comprising: feeding the sliver past a sensing means which generates a signal responsive to irregularities in said sliver; drafting the sliver at varying speeds responsive to the signal generated by the irregularities in the sliver producing an even sliver; guiding the drafted sliver to a passageway in a rotating guidance gear through a plurality of radially varying paths as the speed of the drafting varies, the path that the sliver travels depending on the speed of the drafting; and depositing the sliver into said can in a plurality of multiradius configurations while said guidance gear and said can are rotated at a constant speed.

4. The method of evening the thickness of sliver by drafting with drafting rolls and depositing the sliver in a can without further drafting of the sliver comprising: sensing irregularities in the sliver; varying the speed of the drafting rolls responsive to the sensed irregularities in the sliver for drafting the sliver to provide an even sliver; feeding the sliver through a rotating guide which guides said sliver through a plurality of radiaily varying paths between the drafting rolls and the can, said path being traveled by said sliver depending on the speed of rotation of the drafting rolls; and depositing said sliver into a can driven at a constant speed in a plurality of multiradius configurations.

5. A sliver coiler and the like having a sliver can, driving means rotating the sliver can at uniform speed, and a tube gear driven by the driving means at uniform speed, a pair of drafting rolls feeding sliver for reception by the sliver can, measuring means for sensing variations in the relative thickness of said sliver and for generating a signal responsive thereto, a variable speed transmission through which said drafting rolls are driven, resilient damping means responsive to said signal for smoothing said signal and providing a damped signal indicative of maintained variations in the thickness of the sliver, means for coupling said damping means to said variable speed transmission, said variable speed transmission being controlled responsive to said damped signal for varying the speed of said drafting rolls, whereby variations in sliver thickness are reduced by the drafting which occurs between the measuring means and said drafting rolls driven at a speed controlled responsive to variations in sliver thickness.

6. The device as set forth in claim 5 including; a timedelay means responsive to said signal generated by said measuring means for delaying such signal prior to transmission to said variable speed transmission; whereby said delayed signal causes the drafting to take place between said drafting rolls and said measuring means.

7. In a sliver coiler and the like having a sliver can, a guidance gear, and driving means rotating said guidance gear and can at constant speed, the improvement including: a pair of driven drafting rolls feeding sliver for reception by the sliver can, means varying the speed of said drafting rolls responsive to variations in thickness of the sliver, and a guiding element offering a variable radius path for said sliver between said drafting rolls and said guidance gear as the drafting speed of the sliver varies, said guiding element presenting a progressively larger path for the sliver as the sliver progresses from the drafting rolls into said sliver can, whereby variations in sliver speed may be accommodated by the guiding element without distortion of the sliver thereby.

References Cited ROBERT R. MACKEY, Primary Examiner. 

